This invention relates to a bucket system incorporating a tilting mechanism, which bucket system is attachable to a fork lift.
The inventor has originated a system for converting a fork lift into a wheeled machine capable of dumping waste, scooping up snow and doing other hauling jobs by having mounted on the two-pronged platform of the fork lift a bucket adapted to be automatically tilted by means of cables. In view of the prior art as disclosed by (A) U.S. Pat. No. 2,713,431 filed on July 19, 1955, (B) U.S. Pat. No. 3,877,593 filed on Apr. 15, 1975, (C) Japanese Utility Model Laid-Open Publication No. 156174/1976 published on Dec. 13, 1976, (D) Japanese Utility Model Laid-Open Publication No. 2767/1977 published on Jan. 10, 1977, (E) Japanese Patent Publication No. 11615/1968 published on May 16, 1968 and (F) Japanese Utility Model Publication No. 996/1972 published on Jan. 14, 1974, the inventor now proposes herewith a bucket system incorporating a tilting mechanism, which bucket system is attachable to an ordinary fork lift without need for any special mechanical modification.
Now, the references cited above will be described briefly. Reference (A) discloses a construction having a rotatable bin attached to the lifting unit of a fork lift in such a way that when the lifting unit is raised, the cables connected to the fork lift proper draw the cable arms secured to the bin and consequently cause the bin to be tilted. References (C) and (D) also relate to a mechanism such that a bucket (or bin) mounted on the fork lift proper is tipped over in consequence of the elevation of the lifting unit of the fork lift. In the constructions disclosed by these references, there are invariably incorporated cables which are each connected at one end thereof to the rear portion of a bucket rotatably attached to the leading ends of the prongs of the fork, passed over the upper end of a movable mast of the fork lift, and again connected at the other end thereof to the rear face of the mast opposite the bucket. As the lifting unit is raised, the cables draw up the rear side of the bucket and cause whatever is contained in the bucket to be dumped out. The mechanism disclosed by each of References (A), (C) and (D), therefore, entails a disadvantage that the fork lift itself requires a modification to permit incorporation of the mechanism and the mast of the fork lift requires a great height to provide ample tilting of the bucket. Besides, the cables frequently jeopardize the safety of the fork lift operator as by sliding off the pulleys at the upper ends of the post or by being suddenly broken because of the excessive strain resulting from the extremely sharp bend of the cables on the pulleys.
References (B) and (F) both involve a mechanism whereby the mast of the fork lift and the two-pronged platform are kept in a backwardly slanted state to retain the bucket in its normal horizontal position and they are pushed forwardly to tilt the bucket. Because of the movement thus involved in tilting the bucket, this mechanism suffers from notably inferior operability.
Reference (E) discloses a construction wherein the bucket is divided into a frame member and a cover member and these component members of the bucket are given respective sliding motions required for loading and unloading the bucket. Again in this case, the fork lift suffers from poor operability because the mechanism is complicated.
The conventional bucket systems designed for use on fork lifts are either produced by remodelling conventional fork lifts or designed from the beginning for the exclusive purpose of loading and dumping. Thus, the fork lifts to which such bucket systems are attached cannot be converted into normal fork lifts. This brings about the following disadvantages. A fork-lift-with-bucket designed for scooping up snow, for example, cannot be put to effective use in any season other than the winter. If the same fork-lift-with-bucket is employed for moving dirt, for example, it cannot be used for such jobs as the conveyance of stacks of articles within factory premises, for which a regular fork lift is very well suited. In short, known fork lifts with bucket systems have limited uses.
An object of the present invention is to provide a bucket system incorporating a tilting mechanism which can be attached to any ordinary conventional fork lift without requiring any special modification and can readily be removed from the fork lift when it is desired to use the fork lift by itself.
Another object of the present invention is to provide a bucket system incorporating a mechanism capable of enabling the bucket proper to be tilted with high efficiency, preventing the cables used for drawing the bucket proper from being exposed to excessive stress and to consequent accidental breakage, and precluding the cables from unexpected slippage from the pulleys over which they are trained.
A further object of this invention is to provide a bucket system having a front cover adapted to be automatically opened and closed to suit the purpose of use.